Azinothiadiazole Compounds and Related Semiconductor Devices

ABSTRACT

The present invention relates to new semiconducting compounds having at least one optionally substituted azino[1,2,3]thiadiazole moiety. The compounds disclosed herein can exhibit high carrier mobility and/or efficient light absorption/emission characteristics, and can possess certain processing advantages such as solution-processability and/or good stability at ambient conditions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of U.S. ProvisionalPatent Application Ser. No. 62/253,672 filed on Nov. 10, 2015, thedisclosure of which is incorporated by reference herein in its entirety.

BACKGROUND

Flexible and printed electronics is a revolutionary new concept forfabricating optoelectronic devices using high-throughput, inexpensivesolution processes (e.g., printing methodologies) on flexible plasticfoils, which contrasts sharply with the highly specialized and expensivefacilities and equipment required for silicon fabrication. By using theappropriate materials, these technologies could enable inexpensive,lightweight, flexible, optically transparent, and unbreakable componentsfor displays, cell phones, medical diagnostics, RFID tags, and solarmodules which can then be integrated with textiles, printed batteries,solar cells, and aircraft and satellite structures. The enablingmaterial component of all these technologies (among other essentialmaterials) is the semiconductor where charge transport, lightabsorption, and/or light generation occur. To broaden devicefunctionalities and applications, two types of semiconductors arerequired: p-type (hole-transporting) and n-type (electron-transporting).The use and combination of these two types of semiconductors enables thefabrication of elementary electronic building blocks for drivingdisplays, harvesting light, generating light, carrying out logicoperations, and sensor functions.

Several p- and n-channel molecular semiconductors have achievedacceptable device performance and stability. For example, OTFTs based onacenes and oligothiophenes (p-channel) and perylenes (n-channel) exhibitcarrier mobilities (μ's) >1 cm²/Vs in ambient conditions. However,molecular semiconductors typically are less easily processable viaprinting methodologies than polymeric semiconductors due to solutionviscosity requirements.

Accordingly, the art desires new semiconducting compounds, particularlythose having good stability, processing properties, and/or chargetransport characteristics in ambient conditions.

SUMMARY

In light of the foregoing, the present teachings provide organicsemiconducting compounds that can address various deficiencies andshortcomings of the prior art, including those outlined above. Compoundsaccording to the present teachings can exhibit properties such asoptimized optical absorption, good charge transport characteristics andchemical stability in ambient conditions, low-temperatureprocessability, large solubility in common solvents, and processingversatility (e.g., via various solution processes). As a result,optoelectronic devices such as OPV cells that incorporate one or more ofthe present compounds as a photoactive layer can exhibit highperformance in ambient conditions, for example, demonstrating one ormore of low band-gap, high fill factor, high open circuit voltage, andhigh power conversion efficiency, and preferably all of these criteria.Similarly, other organic semiconductor-based devices such as OTFTs canbe fabricated efficiently using the organic semiconductor materialsdescribed herein.

Generally, the present teachings provide semiconducting compounds thatinclude one or more divalent azino[1,2,3]thiadiazole moieties. Suchdivalent azino[1,2,3]thiadiazole moieties can be represented by formula(I):

where each W independently can be N, CH, or CR¹, where R¹ is asubstituent, and provided that at least one of the W is N. In someembodiments, the present compound is a polymer having one or morerepeating units M₁ each of which includes at least oneazino[1,2,3]thiadiazole moiety, and where the polymer has a degree ofpolymerization (n) ranging from at least 3. In certain embodiments, thepolymer is a homopolymer including only repeating units M₁. In otherembodiments, the polymer also includes at least one other repeating unitM₂ that does not include any azino[1,2,3]thiadiazole moiety. Such M₂unit can be selected from:

wherein pi-2, Ar, Z, m, m′, m″, p, and p′ are as defined herein. In someembodiments, the present compound is a molecular compound including atleast one azino[1,2,3]thiadiazole moiety and a plurality of linearand/or cyclic conjugated moieties, such that the compound as a wholeprovides a pi-extended conjugated system.

The present teachings also provide methods of preparing such compoundsand semiconductor materials based on such compounds, as well as variouscompositions, composites, and devices that incorporate the compounds andsemiconductor materials disclosed herein.

The foregoing as well as other features and advantages of the presentteachings will be more fully understood from the following figures,description, examples, and claims.

BRIEF DESCRIPTION OF DRAWINGS

It should be understood that the drawings described below are forillustration purpose only. The drawings are not necessarily to scale,with emphasis generally being placed upon illustrating the principles ofthe present teachings. The drawings are not intended to limit the scopeof the present teachings in any way.

FIG. 1 illustrates four different configurations of thin filmtransistors: a) bottom-gate top contact, b) bottom-gate bottom-contact,c) top-gate bottom-contact, and d) top-gate top-contact; each of whichcan be used to incorporate one or more compounds of the presentteachings, particularly as the channel (semiconductor) materials.

FIG. 2 illustrates a representative structure of a bulk-heterojunctionorganic photovoltaic device (also known as a solar cell), which canincorporate one or more compounds of the present teachings as the donorand/or acceptor materials.

FIG. 3 illustrates a representative structure of an organiclight-emitting device which can incorporate one or more compounds of thepresent teachings as electron-transporting and/or emissive and/orhole-transporting materials.

DETAILED DESCRIPTION

Throughout the application, where compositions are described as having,including, or comprising specific components, or where processes aredescribed as having, including, or comprising specific process steps, itis contemplated that compositions of the present teachings also consistessentially of, or consist of, the recited components, and that theprocesses of the present teachings also consist essentially of, orconsist of, the recited process steps.

In the application, where an element or component is said to be includedin and/or selected from a list of recited elements or components, itshould be understood that the element or component can be any one of therecited elements or components and can be selected from a groupconsisting of two or more of the recited elements or components.Further, it should be understood that elements and/or features of acomposition, an apparatus, or a method described herein can be combinedin a variety of ways without departing from the spirit and scope of thepresent teachings, whether explicit or implicit herein.

The use of the terms “include,” “includes”, “including,” “have,” “has,”or “having” should be generally understood as open-ended andnon-limiting unless specifically stated otherwise.

The use of the singular herein includes the plural (and vice versa)unless specifically stated otherwise. In addition, where the use of theterm “about” is before a quantitative value, the present teachings alsoinclude the specific quantitative value itself, unless specificallystated otherwise. As used herein, the term “about” refers to a ±10%variation from the nominal value unless otherwise indicated or inferred.

It should be understood that the order of steps or order for performingcertain actions is immaterial so long as the present teachings remainoperable. Moreover, two or more steps or actions may be conductedsimultaneously.

As used herein, a “p-type semiconductor material” or a “donor” materialrefers to a semiconductor material, for example, an organicsemiconductor material, having holes as the majority current or chargecarriers. In some embodiments, when a p-type semiconductor material isdeposited on a substrate, it can provide a hole mobility in excess ofabout 10⁻⁵ cm²/Vs. In the case of field-effect devices, a p-typesemiconductor also can exhibit a current on/off ratio of greater thanabout 10.

As used herein, an “n-type semiconductor material” or an “acceptor”material refers to a semiconductor material, for example, an organicsemiconductor material, having electrons as the majority current orcharge carriers. In some embodiments, when an n-type semiconductormaterial is deposited on a substrate, it can provide an electronmobility in excess of about 10⁻⁵ cm²/Vs. In the case of field-effectdevices, an n-type semiconductor also can exhibit a current on/off ratioof greater than about 10.

As used herein, “mobility” refers to a measure of the velocity withwhich charge carriers, for example, holes (or units of positive charge)in the case of a p-type semiconductor material and electrons (or unitsof negative charge) in the case of an n-type semiconductor material,move through the material under the influence of an electric field. Thisparameter, which depends on the device architecture, can be measuredusing a field-effect device or space-charge limited currentmeasurements.

As used herein, a compound can be considered “ambient stable” or “stableat ambient conditions” when a transistor incorporating the compound asits semiconducting material exhibits a carrier mobility that ismaintained at about its initial measurement when the compound is exposedto ambient conditions, for example, air, ambient temperature, andhumidity, over a period of time. For example, a compound can bedescribed as ambient stable if a transistor incorporating the compoundshows a carrier mobility that does not vary more than 20% or more than10% from its initial value after exposure to ambient conditions,including, air, humidity and temperature, over a 3 day, 5 day, or 10 dayperiod.

As used herein, fill factor (FF) is the ratio (given as a percentage) ofthe actual maximum obtainable power, (P_(m) or V_(mp)*J_(mp)), to thetheoretical (not actually obtainable) power, (J_(sc)*V_(oc)).Accordingly, FF can be determined using the equation:

FF=(V _(mp) *J _(mp))/(J _(sc) *V _(oc))

where J_(mp) and V_(mp) represent the current density and voltage at themaximum power point (P_(m)), respectively, this point being obtained byvarying the resistance in the circuit until J*V is at its greatestvalue; and J_(sc) and V_(oc) represent the short circuit current and theopen circuit voltage, respectively. Fill factor is a key parameter inevaluating the performance of solar cells. Commercial solar cellstypically have a fill factor of about 0.60% or greater.

As used herein, the open-circuit voltage (V_(oc)) is the difference inthe electrical potentials between the anode and the cathode of a devicewhen there is no external load connected.

As used herein, the power conversion efficiency (PCE) of a solar cell isthe percentage of power converted from incident light to electricalpower. The PCE of a solar cell can be calculated by dividing the maximumpower point (P_(m)) by the input light irradiance (E, in W/m²) understandard test conditions (STC) and the surface area of the solar cell(A_(c) in m²). STC typically refers to a temperature of 25° C. and anirradiance of 1000 W/m² with an air mass 1.5 (AM 1.5) spectrum.

As used herein, a component (such as a thin film layer) can beconsidered “photoactive” if it contains one or more compounds that canabsorb photons to produce excitons for the generation of a photocurrent.

As used herein, “solution-processable” refers to compounds (e.g.,polymers), materials, or compositions that can be used in varioussolution-phase processes including spin-coating, printing (e.g., inkjetprinting, gravure printing, offset printing and the like), spraycoating, electrospray coating, drop casting, dip coating, and bladecoating.

As used herein, a “polymeric compound” (or “polymer”) refers to amolecule including a plurality of one or more repeating units connectedby covalent chemical bonds. A polymeric compound can be represented bythe general formula:

*M*

wherein M is the repeating unit or monomer. The polymeric compound canhave only one type of repeating unit as well as two or more types ofdifferent repeating units. When a polymeric compound has only one typeof repeating unit, it can be referred to as a homopolymer. When apolymeric compound has two or more types of different repeating units,the term “copolymer” or “copolymeric compound” can be used instead. Forexample, a copolymeric compound can include repeating units

*M^(a)* and *M^(b)*,

where M^(a) and M^(b) represent two different repeating units. Unlessspecified otherwise, the assembly of the repeating units in thecopolymer can be head-to-tail, head-to-head, or tail-to-tail. Inaddition, unless specified otherwise, the copolymer can be a randomcopolymer, an alternating copolymer, or a block copolymer. For example,the general formula:

*M^(a) _(x)-M^(b) _(y)*

can be used to represent a copolymer of M^(a) and M^(b) having x molefraction of M^(a) and y mole fraction of M^(b) in the copolymer, wherethe manner in which comonomers M^(a) and M^(b) is repeated can bealternating, random, regiorandom, regioregular, or in blocks. Inaddition to its composition, a polymeric compound can be furthercharacterized by its degree of polymerization (n) and molar mass (e.g.,number average molecular weight (M_(n)) and/or weight average molecularweight (M_(w)) depending on the measuring technique(s)).

As used herein, “heteroatom” refers to an atom of any element other thancarbon or hydrogen and includes, for example, nitrogen, oxygen, silicon,sulfur, phosphorus, and selenium.

As used herein, “halo” or “halogen” refers to fluoro, chloro, bromo, andiodo.

As used herein, “oxo” refers to a double-bonded oxygen (i.e., ═O).

As used herein, “alkyl” refers to a straight-chain or branched saturatedhydrocarbon group. Examples of alkyl groups include methyl (Me), ethyl(Et), propyl (e.g., n-propyl and iso-propyl), butyl (e.g., n-butyl,iso-butyl, sec-butyl, tent-butyl), pentyl groups (e.g., n-pentyl,iso-pentyl, neopentyl), hexyl groups, and the like. In variousembodiments, an alkyl group can have 1 to 40 carbon atoms (i.e., C₁₋₄₀alkyl group), for example, 1-20 carbon atoms (i.e., C₁₋₂₀ alkyl group).In some embodiments, an alkyl group can have 1 to 6 carbon atoms, andcan be referred to as a “lower alkyl group.” Examples of lower alkylgroups include methyl, ethyl, propyl (e.g., n-propyl and iso-propyl),and butyl groups (e.g., n-butyl, iso-butyl, sec-butyl, tent-butyl). Insome embodiments, alkyl groups can be substituted as described herein.An alkyl group is generally not substituted with another alkyl group, analkenyl group, or an alkynyl group.

As used herein, “haloalkyl” refers to an alkyl group having one or morehalogen substituents. At various embodiments, a haloalkyl group can have1 to 40 carbon atoms (i.e., C₁₋₄₀ haloalkyl group), for example, 1 to 20carbon atoms (i.e., C₁₋₂₀ haloalkyl group). Examples of haloalkyl groupsinclude CF₃, C₂F₅, CHF₂, CH₂F, CCl₃, CHCl₂, CH₂Cl, C₂Cl₅, and the like.Perhaloalkyl groups, i.e., alkyl groups where all of the hydrogen atomsare replaced with halogen atoms (e.g., CF₃ and C₂F₅), are includedwithin the definition of “haloalkyl.” For example, a C₁-₄₀ haloalkylgroup can have the formula —C_(z)H_(2z+1−t)X⁰ _(t), where X⁰, at eachoccurrence, is F, Cl, Br or I, z is an integer in the range of 1 to 40,and t is an integer in the range of 1 to 81, provided that t is lessthan or equal to 2z+1. Haloalkyl groups that are not perhaloalkyl groupscan be substituted as described herein.

As used herein, “alkoxy” refers to —O-alkyl group. Examples of alkoxygroups include, but are not limited to, methoxy, ethoxy, propoxy (e.g.,n-propoxy and isopropoxy), t-butoxy, pentoxyl, hexoxyl groups, and thelike. The alkyl group in the —O-alkyl group can be substituted asdescribed herein.

As used herein, “alkylthio” refers to an —S-alkyl group. Examples ofalkylthio groups include, but are not limited to, methylthio, ethylthio,propylthio (e.g., n-propylthio and isopropylthio), t-butylthio,pentylthio, hexylthio groups, and the like. The alkyl group in the—S-alkyl group can be substituted as described herein.

As used herein, “alkenyl” refers to a straight-chain or branched alkylgroup having one or more carbon-carbon double bonds. Examples of alkenylgroups include ethenyl, propenyl, butenyl, pentenyl, hexenyl,butadienyl, pentadienyl, hexadienyl groups, and the like. The one ormore carbon-carbon double bonds can be internal (such as in 2-butene) orterminal (such as in 1-butene). In various embodiments, an alkenyl groupcan have 2 to 40 carbon atoms (i.e., C₂₋₄₀ alkenyl group), for example,2 to 20 carbon atoms (i.e., C₂₋₂₀ alkenyl group). In some embodiments,alkenyl groups can be substituted as described herein. An alkenyl groupis generally not substituted with another alkenyl group, an alkyl group,or an alkynyl group.

As used herein, “alkynyl” refers to a straight-chain or branched alkylgroup having one or more triple carbon-carbon bonds. Examples of alkynylgroups include ethynyl, propynyl, butynyl, pentynyl, hexynyl, and thelike. The one or more triple carbon-carbon bonds can be internal (suchas in 2-butyne) or terminal (such as in 1-butyne). In variousembodiments, an alkynyl group can have 2 to 40 carbon atoms (i.e., C₂₋₄₀alkynyl group), for example, 2 to 20 carbon atoms (i.e., C₂₋₂₀ alkynylgroup). In some embodiments, alkynyl groups can be substituted asdescribed herein. An alkynyl group is generally not substituted withanother alkynyl group, an alkyl group, or an alkenyl group.

As used herein, a “cyclic moiety” can include one or more (e.g., 1-6)carbocyclic or heterocyclic rings. In embodiments where the cyclicmoiety is a “polycyclic moiety,” the “polycyclic moiety” can include twoor more rings fused to each other (i.e., sharing a common bond) and/orconnected to each other via a spiro atom. The cyclic moiety can be acycloalkyl group, a heterocycloalkyl group, an aryl group, or aheteroaryl group (i.e., can include only saturated bonds, or can includeone or more unsaturated bonds regardless of aromaticity), and can beoptionally substituted as described herein. In embodiments where thecyclic moiety is a “monocyclic moiety,” the “monocyclic moiety” caninclude a 3-20 membered carbocyclic or heterocyclic ring. A monocyclicmoiety can include a C₆₋₂₀ aryl group (e.g., C₆₋₁₄ aryl group) or a 5-20membered heteroaryl group (e.g., 5-14 membered heteroaryl group), eachof which can be optionally substituted as described herein.

As used herein, “cycloalkyl” refers to a non-aromatic carbocyclic groupincluding cyclized alkyl, alkenyl, and alkynyl groups. In variousembodiments, a cycloalkyl group can have 3 to 20 carbon atoms, forexample, 3 to 14 carbon atoms (i.e., C₃₋₁₄ cycloalkyl group). Acycloalkyl group can be monocyclic (e.g., cyclohexyl) or polycyclic(e.g., containing fused, bridged, and/or spiro ring systems), where thecarbon atoms are located inside or outside of the ring system. Anysuitable ring position of the cycloalkyl group can be covalently linkedto the defined chemical structure. Examples of cycloalkyl groups includecyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl,cyclopentenyl, cyclohexenyl, cyclohexadienyl, cycloheptatrienyl,norbornyl, norpinyl, norcaryl, adamantyl, and spiro[4.5]decanyl groups,as well as their homologs, isomers, and the like. In some embodiments,cycloalkyl groups can be substituted as described herein.

As used herein, “cycloheteroalkyl” refers to a non-aromatic cycloalkylgroup that contains at least one ring heteroatom selected from O, S, Se,N, P, and Si (e.g., O, S, and N), and optionally contains one or moredouble or triple bonds. A cycloheteroalkyl group can have 3 to 20 ringatoms, for example, 3 to 14 ring atoms (i.e., 3-14 memberedcycloheteroalkyl group). One or more N, P, S, or Se atoms (e.g., N or S)in a cycloheteroalkyl ring may be oxidized (e.g., morpholine N-oxide,thiomorpholine S-oxide, thiomorpholine S,S-dioxide). In someembodiments, nitrogen or phosphorus atoms of cycloheteroalkyl groups canbear a substituent, for example, a hydrogen atom, an alkyl group, orother substituents as described herein. Cycloheteroalkyl groups can alsocontain one or more oxo groups, such as oxopiperidyl, oxooxazolidyl,dioxo-(1H,3H)-pyrimidyl, oxo-2(1H)-pyridyl, and the like. Examples ofcycloheteroalkyl groups include, among others, morpholinyl,thiomorpholinyl, pyranyl, imidazolidinyl, imidazolinyl, oxazolidinyl,pyrazolidinyl, pyrazolinyl, pyrrolidinyl, pyrrolinyl, tetrahydrofuranyl,tetrahydrothiophenyl, piperidinyl, piperazinyl, and the like. In someembodiments, cycloheteroalkyl groups can be substituted as describedherein.

As used herein, “aryl” refers to an aromatic monocyclic hydrocarbon ringsystem or a polycyclic ring system in which two or more aromatichydrocarbon rings are fused (i.e., having a bond in common with)together or at least one aromatic monocyclic hydrocarbon ring is fusedto one or more cycloalkyl and/or cycloheteroalkyl rings. An aryl groupcan have 6 to 22 carbon atoms in its ring system (e.g., C₆₋₁₄ arylgroup), which can include multiple fused rings. In some embodiments, apolycyclic aryl group can have from 8 to 22 carbon atoms. Any suitablering position of the aryl group can be covalently linked to the definedchemical structure. Examples of aryl groups having only aromaticcarbocyclic ring(s) include phenyl, 1-naphthyl (bicyclic), 2-naphthyl(bicyclic), anthracenyl (tricyclic), phenanthrenyl (tricyclic),pentacenyl (pentacyclic) and like groups. Examples of polycyclic ringsystems in which at least one aromatic carbocyclic ring is fused to oneor more cycloalkyl and/or cycloheteroalkyl rings include, among others,benzo derivatives of cyclopentane (i.e., an indanyl group, which is a5,6-bicyclic cycloalkyl/aromatic ring system), cyclohexane (i.e., atetrahydronaphthyl group, which is a 6,6-bicyclic cycloalkyl/aromaticring system), imidazoline (i.e., a benzimidazolinyl group, which is a5,6-bicyclic cycloheteroalkyl/aromatic ring system), and pyran (i.e., achromenyl group, which is a 6,6-bicyclic cycloheteroalkyl/aromatic ringsystem). Other examples of aryl groups include benzodioxanyl,benzodioxolyl, chromanyl, indolinyl groups, and the like. In someembodiments, aryl groups can be substituted as described herein. In someembodiments, an aryl group can have one or more halogen substituents,and can be referred to as a “haloaryl” group. Perhaloaryl groups, i.e.,aryl groups where all of the hydrogen atoms are replaced with halogenatoms (e.g., —C₆F ₅), are included within the definition of “haloaryl.”In certain embodiments, an aryl group is substituted with another arylgroup and can be referred to as a biaryl group. Each of the aryl groupsin the biaryl group can be substituted as disclosed herein.

As used herein, “arylalkyl” refers to an -alkyl-aryl group, where thearylalkyl group is covalently linked to the defined chemical structurevia the alkyl group. An arylalkyl group is within the definition of a—Y—C₆₋₁₄ aryl group, where Y is as defined herein. An example of anarylalkyl group is a benzyl group (—CH₂—C₆H₅). An arylalkyl group can beoptionally substituted, i.e., the aryl group and/or the alkyl group, canbe substituted as disclosed herein.

As used herein, “heteroaryl” refers to an aromatic monocyclic ringsystem containing at least one ring heteroatom selected from oxygen (O),nitrogen (N), sulfur (S), silicon (Si), and selenium (Se) or apolycyclic ring system where at least one of the rings present in thering system is aromatic and contains at least one ring heteroatom.Polycyclic heteroaryl groups include two or more heteroaryl rings fusedtogether and monocyclic heteroaryl rings fused to one or more aromaticcarbocyclic rings, non-aromatic carbocyclic rings, and/or non-aromaticcycloheteroalkyl rings. A heteroaryl group, as a whole, can have, forexample, 5 to 22 ring atoms and contain 1-5 ring heteroatoms (i.e., 5-20membered heteroaryl group). The heteroaryl group can be attached to thedefined chemical structure at any heteroatom or carbon atom that resultsin a stable structure. Generally, heteroaryl rings do not contain O—O,S—S, or S—O bonds. However, one or more N or S atoms in a heteroarylgroup can be oxidized (e.g., pyridine N-oxide, thiophene S-oxide,thiophene S,S-dioxide). Examples of heteroaryl groups include, forexample, the 5- or 6-membered monocyclic and 5-6 bicyclic ring systemsshown below:

where T is O, S, NH, N-alkyl, N-aryl, N-(arylalkyl) (e.g., N-benzyl),SiH₂, SiH(alkyl), Si(alkyl)₂, SiH(arylalkyl), Si(arylalkyl)₂, orSi(alkyl)(arylalkyl). Examples of such heteroaryl rings includepyrrolyl, furyl, thienyl, pyridyl, pyrimidyl, pyridazinyl, pyrazinyl,triazolyl, tetrazolyl, pyrazolyl, imidazolyl, isothiazolyl, thiazolyl,thiadiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, indolyl, isoindolyl,benzofuryl, benzothienyl, quinolyl, 2-methylquinolyl, isoquinolyl,quinoxalyl, quinazolyl, benzotriazolyl, benzimidazolyl, benzothiazolyl,benzisothiazolyl, benzisoxazolyl, benzoxadiazolyl, benzoxazolyl,cinnolinyl, IH-indazolyl, 2H-indazolyl, indolizinyl, isobenzofuyl,naphthyridinyl, phthalazinyl, pteridinyl, purinyl, oxazolopyridinyl,thiazolopyridinyl, imidazopyridinyl, furopyridinyl, thienopyridinyl,pyridopyrimidinyl, pyridopyrazinyl, pyridopyridazinyl, thienothiazolyl,thienoxazolyl, thienoimidazolyl groups, and the like. Further examplesof heteroaryl groups include 4,5,6,7-tetrahydroindolyl,tetrahydroquinolinyl, benzothienopyridinyl, benzofuropyridinyl groups,and the like. In some embodiments, heteroaryl groups can be substitutedas described herein.

Compounds of the present teachings can include a “divalent group”defined herein as a linking group capable of forming a covalent bondwith two other moieties. For example, compounds of the present teachingscan include a divalent C₁₋₂₀ alkyl group (e.g., a methylene group), adivalent C₂₋₂₀ alkenyl group (e.g., a vinylyl group), a divalent C₂₋₂₀alkynyl group (e.g., an ethynylyl group). a divalent C₆₋₁₄ aryl group(e.g., a phenylyl group); a divalent 3-14 membered cycloheteroalkylgroup (e.g., a pyrrolidylyl), and/or a divalent 5-14 membered heteroarylgroup (e.g., a thienylyl group).

The electron-donating or electron-withdrawing properties of severalhundred of the most common substituents, reflecting all common classesof substituents have been determined, quantified, and published. Themost common quantification of electron-donating and electron-withdrawingproperties is in terms of Hammett σ values. Hydrogen has a Hammett σvalue of zero, while other substituents have Hammett σ values thatincrease positively or negatively in direct relation to theirelectron-withdrawing or electron-donating characteristics. Substituentswith negative Hammett σ values are considered electron-donating, whilethose with positive Hammett σ values are consideredelectron-withdrawing. See Lange's Handbook of Chemistry, 12th ed.,McGraw Hill, 1979, Table 3-12, pp. 3-134 to 3-138, which lists Hammett σvalues for a large number of commonly encountered substituents and isincorporated by reference herein.

It should be understood that the term “electron-accepting group” can beused synonymously herein with “electron acceptor” and“electron-withdrawing group”. In particular, an “electron-withdrawinggroup” (“EWG”) or an “electron-accepting group” or an“electron-acceptor” refers to a functional group that draws electrons toitself more than a hydrogen atom would if it occupied the same positionin a molecule. Examples of electron-withdrawing groups include, but arenot limited to, halogen or halo (e.g., F, Cl, Br, I), —NO₂, —CN, —NC,—S(R⁰)₂ ⁺, —N(R⁰)₃ ⁺, —SO₃H, —SOR⁰, SO₃R⁰, —SO₂NHR⁰, SO₂N(R⁰)₂, —COOH,—COR⁰, —COOR⁰, —CONHR⁰, —CON(R⁰)₂, C₁₋₄₀ haloalkyl groups, C₆₋₁₄ arylgroups, and 5-14 membered electron-poor heteroaryl groups; where R⁰ is aC₁₋₂₀ alkyl group, a C₂₋₂₀ alkenyl group, a C₂₋₂₀ alkynyl group, a C₁₋₂₀haloalkyl group, a C₁₋₂₀ alkoxy group, a C₆₋₁₄ aryl group, a C₃₋₁₄cycloalkyl group, a 3-14 membered cycloheteroalkyl group, and a 5-14membered heteroaryl group, each of which can be optionally substitutedas described herein. For example, each of the C₁₋₂₀ alkyl group, theC₂₋₂₀ alkenyl group, the C₂₋₂₀ alkynyl group, the C₁₋₂₀ haloalkyl group,the C₁₋₂₀ alkoxy group, the C₆₋₁₄ aryl group, the C₃₋₁₄ cycloalkylgroup, the 3-14 membered cycloheteroalkyl group, and the 5-14 memberedheteroaryl group can be optionally substituted with 1-5 smallelectron-withdrawing groups such as F, Cl, Br, —NO₂, —CN, —NC, —S(R⁰)₂⁺, —N(R⁰)₃ ⁺, —SO₃H, —SO₂R⁰, —SO₃R⁰, —SO₂NHR⁰, —SO₂N(R⁰)₂, —COOH, —COR⁰,—COOR⁰, —CONHR⁰, and —CON(R⁰)₂.

It should be understood that the term “electron-donating group” can beused synonymously herein with “electron donor”. In particular, an“electron-donating group” or an “electron-donor” refers to a functionalgroup that donates electrons to a neighboring atom more than a hydrogenatom would if it occupied the same position in a molecule. Examples ofelectron-donating groups include —OH, —OR⁰, —NH₂, —NHR⁰, —N(R⁰)₂, and5-14 membered electron-rich heteroaryl groups, where R⁰ is a C₁₋₂₀ alkylgroup, a C₂₋₂₀ alkenyl group, a C₂₋₂₀ alkynyl group, a C₆₋₁₄ aryl group,or a C₃₋₁₄ cycloalkyl group.

Various unsubstituted heteroaryl groups can be described aselectron-rich (or π-excessive) or electron-poor (or π-deficient). Suchclassification is based on the average electron density on each ringatom as compared to that of a carbon atom in benzene. Examples ofelectron-rich systems include 5-membered heteroaryl groups having oneheteroatom such as furan, pyrrole, and thiophene; and their benzofusedcounterparts such as benzofuran, benzopyrrole, and benzothiophene.Examples of electron-poor systems include 6-membered heteroaryl groupshaving one or more heteroatoms such as pyridine, pyrazine, pyridazine,and pyrimidine; as well as their benzofused counterparts such asquinoline, isoquinoline, quinoxaline, cinnoline, phthalazine,naphthyridine, quinazoline, phenanthridine, acridine, and purine. Mixedheteroaromatic rings can belong to either class depending on the type,number, and position of the one or more heteroatom(s) in the ring. SeeKatritzky, A. R and Lagowski, J. M., Heterocyclic Chemistry (John Wiley& Sons, New York, 1960).

At various places in the present specification, substituents of monomersA and B are disclosed in groups or in ranges. It is specificallyintended that the description include each and every individualsubcombination of the members of such groups and ranges. For example,the term “C₁₋₆ alkyl” is specifically intended to individually discloseC₁, C₂, C₃, C₄, C₅, C₆, C₁-C₆, C₁-C₅, C₁-C₄, C₁-C₃, C₁-C₂, C₂-C₆, C₂-C₅,C₂-C₄, C₂-C₃, C₃-C₆, C₃-C₅, C₃- C₄, C₄-C₆, C₄-C₅, and C₅-C₆ alkyl. Byway of other examples, an integer in the range of 0 to 40 isspecifically intended to individually disclose 0, 1, 2, 3, 4, 5, 6, 7,8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, and 40, and aninteger in the range of 1 to 20 is specifically intended to individuallydisclose 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,19, and 20. Additional examples include that the phrase “optionallysubstituted with 1-5 substituents” is specifically intended toindividually disclose a chemical group that can include 0, 1, 2, 3, 4,5, 0-5, 0-4, 0-3, 0-2, 0-1, 1-5, 1-4, 1-3, 1-2, 2-5, 2-4, 2-3, 3-5, 3-4,and 4-5 substituents.

Compounds described herein can contain an asymmetric atom (also referredas a chiral center) and some of the compounds can contain two or moreasymmetric atoms or centers, which can thus give rise to optical isomers(enantiomers) and diastereomers (geometric isomers). The presentteachings include such optical isomers and diastereomers, includingtheir respective resolved enantiomerically or diastereomerically pureisomers (e.g., (+) or (−) stereoisomer) and their racemic mixtures, aswell as other mixtures of the enantiomers and diastereomers. In someembodiments, optical isomers can be obtained in enantiomericallyenriched or pure form by standard procedures known to those skilled inthe art, which include, for example, chiral separation, diastereomericsalt formation, kinetic resolution, and asymmetric synthesis. Thepresent teachings also encompass cis- and trans-isomers of compoundscontaining alkenyl moieties (e.g., alkenes, azo, and imines). It alsoshould be understood that compounds of the present teachings encompassall possible regioisomers in pure form and mixtures thereof. It may bepossible to separate such isomers, for example, using standardseparation procedures known to those skilled in the art, for example,column chromatography, thin-layer chromatography, simulated moving-bedchromatography, and high-performance liquid chromatography. However,mixtures of regioisomers can be used similarly to the uses of eachindividual regioisomer of the present teachings.

It is specifically contemplated that the depiction of one regioisomerincludes any other regioisomers and any regioisomeric mixtures unlessspecifically stated otherwise.

As used herein, a “leaving group” (“LG”) refers to a charged oruncharged atom (or group of atoms) that can be displaced as a stablespecies as a result of, for example, a substitution or eliminationreaction. Examples of leaving groups include, but are not limited to,halogen (e.g., Cl, Br, I), azide (N₃), thiocyanate (SCN), nitro (NO₂),cyanate (CN), water (H₂O), ammonia (NH₃), and sulfonate groups (e.g.,OSO₂—R, wherein R can be a C₁₋₁₀ alkyl group or a C₆₋₁₄ aryl group eachoptionally substituted with 1-4 groups independently selected from aC₁₋₁₀ alkyl group and an electron-withdrawing group) such as tosylate(toluenesulfonate, OTs), mesylate (methanesulfonate, OMs), brosylate(p-bromobenzenesulfonate, OBs), nosylate (4-nitrobenzenesulfonate, ONs),and triflate (trifluoromethanesulfonate, OTf).

Throughout the specification, structures may or may not be presentedwith chemical names. Where any question arises as to nomenclature, thestructure prevails.

The present teachings relate to molecular and polymeric compounds thatcan be used as organic semiconductor materials. The present compoundscan have good solubility in various common organic solvents and goodstability in air. When incorporated into optical, electronic oroptoelectronic devices including, but not limited to, organicphotovoltaic or solar cells, organic light emitting diodes, and organicfield effect transistors, the present compounds can confer variousdesirable performance properties.

More specifically, the present teachings provide semiconductingcompounds that include one or more optionally substitutedazino[1,2,3]thiadiazole moieties. The optionally substitutedazino[1,2,3]thiadiazole moieties can be represented by formula (I):

wherein each W independently is selected from the group consisting of N,CH, and CR¹, provided that at least one of the W is N; and whereinR¹ is selected from the group consisting of halogen, —CN, NO₂, R²,-L-R³, OH, OR², OR³, NH₂, NHR² _(, N(R) ²)₂, NR² _(R) ³, N(_(R) ³)₂, SH,SR², SR³, S(O)₂OH, —S(O)₂OR², —S(O)₂OR³, C(O)H, C(O)R², C(O)R³, C(O)OH,C(O)OR², C(O)OR³, C(O)NH₂, C(O)NHR², C(O)N(R²)₂, C(O)NR²R³, C(O)N(R³)₂,SiH₃, SiH(R²)₂, SiH₂(R²), and Si(R²)₃, wherein L is selected from thegroup consisting of a divalent C₁₋₄₀ alkyl group, a divalent C₂₋₄₀alkenyl group, a divalent C₁₋₄₀ haloalkyl group, and a covalent bond; R²is selected from a C₁₋₄₀ alkyl group, a C₂₋₄₀ alkenyl group, a C₂₋₄₀alkynyl group, and a C₁₋₄₀ haloalkyl group; and R³ is selected from thegroup consisting of a C₃₋₁₀ cycloalkyl group, a C₆₋₁₄ aryl group, aC₆₋₁₄ haloaryl group, a 3-12 membered cycloheteroalkyl group, and a 5-14membered heteroaryl group, each of which optionally is substituted with1-5 substituents independently selected from the group consisting ofhalogen, —CN, NO₂, R², OR², and SR².

In preferred embodiments, le is selected from the group consisting of F,Cl, Br, I, —CN, —NO₂, R², OR², and SR², where R² can be selected fromthe group consisting of a linear or branched C₁₋₁₀ alkyl group, a linearor branched C₂₋₁₀ alkenyl group, and a linear or branched C₁₋₁₀haloalkyl group. In certain embodiments, R¹ can be selected from thegroup consisting of F, Cl, Br, I, —CN, —NO₂, CH₃, OCH₃, CF₃, and aphenyl group. For example, in the moiety represented by formula (I), oneof the W can be N and the other W can be selected from the groupconsisting of N, CH, CF, CCl, and C(C₁₋₄₀ alkyl group).

In some embodiments, the present compound is a polymer having one ormore repeating units M₁, where each M₁ includes at least one optionallysubstituted azino[1,2,3]thiadiazole moiety represented by formula (I),and where the polymer has a degree of polymerization (n) ranging from atleast 3.

Other than azino[1,2,3]thiadiazole moieties, repeating units M₁optionally can include one or more spacers (Sp) which can be eithernon-cyclic (Z) or cyclic, particularly monocyclic (Ar) or polycyclic(pi-2), which together with the azino[1,2,3]thiadiazole moieties providea pi-extended conjugated group. For example, M₁ can be selected from thegroup consisting of:

wherein:pi-2 is an optionally substituted conjugated polycyclic moiety;Ar, at each occurrence, independently is an optionally substituted 5- or6-membered aryl or heteroaryl group;Z is a conjugated noncyclic linker;m and m′ independently are 0, 1, 2, 3, 4, 5 or 6, provided that at leastone of m and m′ is not 0; andp and p′ independently are 0 and 1, provided that at least one of p andp′ is 1.

To illustrate, the polycyclic conjugated moiety, pi-2, can be anoptionally substituted C₈₋₂₆ aryl group or 8-26 membered heteroarylgroup. For example, pi-2 can have a planar and pi-extended conjugatedcyclic core which can be optionally substituted as disclosed herein.Examples of suitable cyclic cores include naphthalene, anthracene,tetracene, pentacene, perylene, pyrene, coronene, fluorene, indacene,indenofluorene, and tetraphenylene, as well as their analogs in whichone or more carbon atoms can be replaced with a heteroatom such as O, S,Si, Se, N, or P.

In certain embodiments, pi-2 can be selected from the group consistingof:

wherein:R^(a) is selected from the group consisting of H, F, Cl, —CN, R, —OR,—SR, —C(O)R, —OC(O)R, and —C(O)OR;R^(b) is selected from the group consisting of H, R, and -L-R^(f);

R^(c) is H or R;

R^(d) is selected from the group consisting of H, F, Cl, —CN, R, —OR,—SR, —C(O)R, —OC(O)R, —C(O)OR, and -L-R^(f);R^(e) is selected from the group consisting of H, F, Cl, —CN, R, —OR,—SR, —C(O)R, —OC(O)R, —C(O)OR, and R^(f);R^(f) is a C₆₋₂₀ aryl group or a 5-20-membered heteroaryl group, eachoptionally substituted with 1-8 groups independently selected from thegroup consisting of F, Cl, —CN, R, —OR, and —SR; L is selected from thegroup consisting of —O—, —S—, —C(O)—, —OC(O)—, —C(O)O—, and a covalentbond; andR is selected from the group consisting of a C₁₋₄₀ alkyl group, a C₁₋₄₀haloalkyl group, a C₂₋₄₀ alkenyl group, and a C₂₋₄₀ alkynyl group.

The monocyclic conjugated moiety, Ar, at each occurrence, independentlycan be an optionally substituted 5- or 6-membered (hetero)aryl group.For example, Ar can be selected from the group consisting of a phenylgroup, a thienyl group, a thiazolyl group, an isothiazolyl group, athiadiazolyl group, a furyl group, an oxazolyl group, an isoxazolylgroup, an oxadiazolyl group, a pyrrolyl group, a triazolyl group, atetrazolyl group, a pyrazolyl group, an imidazolyl group, a pyridylgroup, a pyrimidyl group, a pyridazinyl group, and a pyrazinyl group,each of which optionally can be substituted with 1-4 R⁵ groupsindependently selected from a halogen, CN, a C₁₋₄₀ alkyl group, a C₁₋₄₀haloalkyl group, a C₁₋₄₀ alkoxy group, and a C₁₋₄₀ alkylthio group.

By way of example, each Ar in (Ar)_(m) and/or (Ar)_(m′) that is present(i.e., when m and/or m′ is 1, 2, 3, 4, 5 or 6) can be represented by:

where each X independently can be selected from the group consisting ofN, CH, and CR⁴, wherein R⁴ can be selected from the group consisting ofF, Cl, —CN, R², OR², SR², C(O)R², OC(O)R², and C(O)OR², where R² is asdefined herein. To illustrate further, (Ar)_(m) or (Ar)_(m′) whenpresent can be selected from the group consisting of:

where, for example, each R⁴ independently is selected from the groupconsisting of F, Cl, CN, R², OR², and SR², where R² is a linear orbranched C₁₋₄₀ alkyl or haloalkyl group.

The conjugated noncyclic linker, Z, can include one or more double ortriple bonds. For example, Z can be a divalent ethenyl group (i.e.,having one double bond), a divalent ethynyl group (i.e., having onetripe bond), a C₄₋₄₀ alkenyl or alkynyl group that includes two or moreconjugated double or triple bonds, or some other linear or branchedconjugated systems that can include heteroatoms such as Si, N, P, andthe like. In certain embodiments, Z can be selected from:

wherein R⁴ is as defined herein. In particular embodiments, Z can beselected from:

In preferred embodiments, the present polymer includes a repeating unitM₁ selected from the group consisting of:

where Ar, R¹, and m′ are as defined herein.

More preferably, M₁ is selected from the group consisting of:

wherein R⁴ can be selected from the group consisting of R², OR², andSR², where R² is a linear or branched C₁₋₄₀ alkyl or haloalkyl group.

In certain embodiments, the present polymer can be a homopolymerincluding only identical repeating units M₁. In other embodiments, thepolymer can be a copolymer including two or more different repeatingunits M₁. In yet other embodiments, the polymer can be a copolymerincluding at least one repeating unit M₁ and at least one otherrepeating unit M₂ that does not include any azino[1,2,3]thiadiazolemoiety. Such M₂ units can include one or more non-cyclic (Z), monocyclic(Ar), and/or polycyclic (pi-2) conjugated linkers, which togetherprovide a pi-extended conjugated group. For example, M₂ can be selectedfrom:

wherein pi-2, Ar, Z, m, m′, m″, p, and p′ are as defined herein.

To illustrate, in certain embodiments, M₂ can have the formula:

wherein m″ is selected from 1, 2, 3, or 4; and Ar is as defined herein.For example, M₂ can be selected from the group consisting of:

where, for example, each R⁴ independently is selected from F, Cl, CN,R², OR², and SR², where R² is a linear or branched C₁₋₄₀ alkyl orhaloalkyl group.

In other embodiments, M₂ can have the formula:

wherein pi-2 can be selected from:

wherein:R^(a) is selected from the group consisting of H, F, Cl, —CN, R, —OR,—SR, —C(O)R, —OC(O)R, and —C(O)OR;R^(b) is selected from the group consisting of H, R, and -L-R^(f);

R^(c) is H or R;

R^(d) is selected from the group consisting of H, F, Cl, —CN, R, —OR,—SR, —C(O)R, —OC(O)R, —C(O)OR, and -L-R^(f);R^(e) is selected from the group consisting of H, F, Cl, —CN, R, —OR,—SR, —C(O)R, —OC(O)R, —C(O)OR, and R^(f);R^(f) is a C₆₋₂₀ aryl group or a 5-20-membered heteroaryl group, eachoptionally substituted with 1-8 groups independently selected from thegroup consisting of F, Cl, —CN, R, —OR, and —SR; L is selected from thegroup consisting of —O—, —S—, —C(O)—, —OC(O)—, —C(O)O—, and a covalentbond; andR is selected from the group consisting of a C₁₋₄₀ alkyl group, a C₁₋₄₀haloalkyl group, a C₂₋₄₀ alkenyl group, and a C₂₋₄₀ alkynyl group.

In yet other embodiments, M₂ can have the formula:

wherein Ar, pi-2, m and m′ are as defined herein. Preferably, (Ar)_(m)and (Ar)_(m′) are selected from:

where R⁴ is as defined herein, and pi-2 is selected from:

wherein:R^(a) is selected from the group consisting of H, F, Cl, —CN, R, —OR,—SR, —C(O)R, —OC(O)R, and —C(O)OR;R^(b) is selected from the group consisting of H, R, and —L—R^(f);

R^(c) is H or R;

R^(d) is selected from the group consisting of H, F, Cl, —CN, R, —OR,—SR, —C(O)R, —OC(O)R, —C(O)OR, and -L-R^(f);R^(e) is selected from the group consisting of H, F, Cl, —CN, R, —OR,—SR, —C(O)R, —OC(O)R, —C(O)OR, and R^(f);R^(f) is a C₆₋₂₀ aryl group or a 5-20-membered heteroaryl group, eachoptionally substituted with 1-8 groups independently selected from thegroup consisting of F, Cl, —CN, R, —OR, and —SR; L is selected from thegroup consisting of —O—, —S—, —C(O)—, —OC(O)—, —C(O)O—, and a covalentbond; andR is selected from the group consisting of a C₁₋₄₀ alkyl group, a C₁₋₄₀haloalkyl group, a C₂₋₄₀ alkenyl group, and a C₂₋₄₀ alkynyl group.

In other embodiments, M₂ can have a formula selected from:

wherein m, m′ and m″ independently are 1, 2, 3 or 4; and Ar, pi-2 and Zare as defined herein. In such embodiments, M₂ can be selected from thegroup consisting of:

wherein R⁴ is as defined herein.

In preferred embodiments, the present polymers are copolymers of M₁ andat least one M₂, where M₂ is selected from:

where pi-2, Ar, m, m′, and m′″ are as defined herein.

Certain embodiments of the present copolymers can be represented by aformula selected from the group consisting of:

where M_(1A) and M_(1B) represent different repeating units M₁, andM_(2A) and M_(2B) represent different repeating units M₂, x and y arereal numbers representing molar ratios, and n is the degree ofpolymerization. To illustrate, M_(1A) and M_(1B) can be:

where R⁴ can be selected from R², OR², and SR², where R² is a linear orbranched C₁₋₄₀ alkyl or haloalkyl group. To illustrate further, M_(2A)and M_(2B) can be:

or two repeating units represented by:

where in M_(2A), Ar is

and in M_(2B), Ar is

For the various polymers described above, the degree of polymerization(n) can be an integer between 3 and 1,000. In some embodiments, n can be4-1,000, 5-1,000, 6-1,000, 7-1,000, 8-1,000, 9-1,000, or 10-1,000. Forexample, n can be 8-500, 8-400, 8-300, or 8-200. In certain embodiments,n can be 8-100. Embodiments of the present compounds including two ormore different repeating units can have such repeating units repeatingin a random or alternating manner, and the mole fraction of the twounits can be between about 0.05 and about 0.95. For example, therespective mole fractions (x and y) of the two units can be betweenabout 0.1 and about 0.9, between about 0.2 and about 0.8, between about0.3 and about 0.7, between about 0.4 and about 0.6, or between about0.45 and about 0.55. In certain embodiments, the present polymers caninclude the same mole fraction of the first unit as the second unit(i.e., x=y=0.5).

In some embodiments, the present compound can be a molecular compoundincluding at least one azino[1,2,3]thiadiazole moiety and a plurality oflinear and/or cyclic conjugated moieties, such that the compound as awhole provides a pi-extended conjugated system.

To illustrate, exemplary small-molecule semiconducting compoundsincluding at least one azino[1,2,3]thiadiazole moiety and monomers forpreparing the polymers described herein can be represented by thefollowing formulae:

where Q¹ can be X¹ or T¹, Q² can be X² or T², where X¹ and X² can beidentical or different reactive groups such as a halide, an organotingroup, a boronate, or a polymerizable group, T¹ and T² can be identicalor different terminal groups selected from H, R², and C(O)R², where R²is a C₁₋₄₀ alkyl or haloalkyl group, and pi-2, Ar, Z, m, m′, m″, p, andp′ are as defined herein.

Certain embodiments of molecular semiconducting compounds according tothe present teachings can be represented by a formula selected from:

where R′, R², m and m′ are as defined herein.

Specific exemplary molecular semiconducting compounds according to thepresent teachings include:

Azino[1,2,3]thiadiazole and monomers including azino[1,2,3]thiadiazoleaccording to the present teachings can be prepared using the syntheticroutes described hereinbelow. Other monomers according to the presentteachings can be commercially available, known in the literature, or canbe prepared from readily prepared intermediates by employing standardsynthetic methods and procedures known to those skilled in the art.Standard synthetic methods and procedures for the preparation of organicmolecules and functional group transformations and manipulations can bereadily obtained from the relevant scientific literature or fromstandard textbooks in the field.

Unsubstituted azino[1,2,3]thiadiazoles can be synthesized viadiazotation (the formation of a diazonium compound) followed by ringclosure, e.g.,

according, but not limited, to the synthetic routes described in theliterature for benzenoid[1,2,3]thiadiazoles. See e.g., Trusova, M. E. etal., Synthesis, 13: 2154-2158 (2011); Ward, E. R. et al., J. Chem. Soc.,2374-2379 (1962); and Hunig, S. et al., Justus Liebigs Annalen derChemie, 738: 192-194 (1970).

Because the reaction intermediate is a diazonium salt, any reagentcapable of forming an aryl diazonium salt from the arylamine can be usedfor preparing the azino[1,2,3]thiadiazole ring and its derivatives.Examples of diazotation methodologies can be found in Butler, R. N.,Chemical Reviews, 75(2): 241-257 (1975); and in O'Leary, P., Sci.Synth., 31b, 1361-1400 (2007).

The following azinoaminothiols are known in the literature:

see preparation in Tetrahedron Letters, 51(21): 2800-2802 (2010); andPharmaceutical Bulletin, 3: 356-60 (1955);

see preparation in Heterocycles, 88(1): 175-178 (2014); and SulfurLetters, 17(4): 197-216 (1994); and

see preparation in Journal of Heterocyclic Chemistry, 20(4): 1047-51(1983); and Science of Synthesis, 17: 117-221 (2004).

In addition, the following substituted azidoaminothiols are eithercommercially available or known in the literature:

Various substituted and unsubstituted azino[1,2,3]thiadiazoles can behalogenated or otherwise provided with reactive groups (Q) to enablecoupling with the various Sp groups (Ar, Z, and/or pi-2) describedherein. For example, monohalogenated azino[1,2,3]thiadiazole derivativescan be useful synthones for the synthesis ofazino[1,2,3]thiadiazole-based small-molecule semiconductors orregioregular polymers.

To illustrate, azino[1,2,3]thiadiazoles can be brominated to providemonobrominated or dibrominated derivatives, which in turn can be used tocouple with other azino[1,2,3]thiadiazoles and/or different conjugatedmoieties having complementary reactive groups (as described below) toprovide various molecular and polymeric semiconductors according to thepresent teachings. For example, monobrominated azino[1,2,3]thiadiazolescan be synthesized from the corresponding precursors using conventionalbromination protocols where a stoichiometric amount of halogen isemployed to optimize monobromination:

Additionally, because two isomers can form, the ratio of the twocompounds can be controlled by changing the experimental conditions suchas temperature, time, concentration, solvent, and brominating reagent.

An alternative route to monobrominated azino[1,2,3]thiadiazoles is tostart with monobrominated azinoaminothiols and build the thiadiazolering via diazotation:

From these monobrominated azino[1,2,3]thiadiazole derivatives, dimericcompounds including two moieties of formula (I) and one or more linearand/or cyclic conjugated moieties (represented by M2 below) can besynthesized as follows:

Dibromoazino[1,2,3]thiadiazoles can be synthesized from thecorresponding precursors using conventional bromination protocols wheretwo times the stoichiometric amount of halogen is employed to optimizedibromination:

Similar to the monobrominated version, it is also possible to start withdibrominated azinoaminothiols and build the thiadiazole ring viadiazotation:

An alternative route is to hydrolyze dibrominated thiazoloazines toprovide dibrominated azinooaminothiols, followed by diazotation:

Brominated thiazoloazines can be synthesized according to various routesreported in the journal and patent literature. See e.g., Bulletin de laSociete Chimique de France, 4: 1491-1496 (1971); Comptes Rendus desSeances de l'Academie des Sciences, Series C: Sciences Chimiques (1966),263(22): 1385-1387 (1966); and Japan Patent Publication No. JP2012119502.

For embodiments where the present compound is a polymer having the M₁unit:

azino[1,2,3]thiadiazoles that are brominated or otherwise derivatizedwith reactive groups can serve as a key building block.

Other polymerizable derivatives of azino[1,2,3]thiadiazole includedistannylated azino[1,2,3]thiadiazoles and diborylatedazino[1,2,3]thiadiazoles.

Distannylated azino[1,2,3]thiadiazole derivatives can be synthesizedaccording to the scheme below.

Conditions for catalytic stannylation are known by those skilled in theart. See e.g., Woo, C. H. et al., JACS, 130(48): 16324-16329 (2008).Diborylated azino[1,2,3]thiadiazole derivatives can be synthesizedaccording to the scheme below.

Conditions for catalytic borylation are known by those skilled in theart. See e.g., Zhao, Y. et al., Tetrahedron, 68(44): 9113-9118 (2012).

The brominated or metallated azino[1,2,3]thiadiazole derivatives thencan be used as an M₁ unit for copolymerization with an M₂ unit havingcomplementary reactive groups. Or, the brominated or metallatedazino[1,2,3]thiadiazole can be reacted with one or more Sp groups havingcomplementary reactive groups to provide a pi-extended semiconductingcompound. Suitable complementary reactive groups used in variouscoupling or polymerization reactions are well known in the art. Inparticular, Stille coupling or Suzuki coupling reactions can be used asdescribed in Yamamoto, J. Organomet. Chem., 653: 195-199 (2002); Waltonet al., Polymer Chemistry (Fred J. Davis ed. 2004), p. 158-187; andGalbrecht et al., Macromolecular Rapid Communications, 28(4): 387-394(2007).

The homopolymerization of M₁ and the copolymerization of M₁ and M₂ canbe achieved via various reactions known to those skilled in the art,including procedures analogous to those described in , the entiredisclosure of each of which is incorporated by reference herein for allpurposes. to prepare polymeric compounds according to the presentteachings with high molecular weights and in high yields (≧75%) andpurity, as confirmed by ¹H NMR spectra, elemental analysis, and/or GPCmeasurements. The scheme below outlines several exemplary reactions thatcan be used to polymerize M₁ by itself or copolymerize M₁ with M₂. Itshould be understood that the polymerizable groups (e.g., SnR₃, BR₂,MgX, ZnX, and Br, where X is a halogen and R is an alkyl group) can bereversed between M₁ and M₂.

The schemes immediately below illustrate the coupling of a dibrominatedazino[1,2,3]thiadiazole derivative with a dimetallated derivative of api-2 moiety:

The reactions described above can be used analogously to couple adibrominated azino[1,2,3]thiadiazole derivative to an Sp group havingcomplementary reactive groups to provide a more extended M₁ unit suchas:

For example, a dibrominated azino[1,2,3]thiadiazole derivative can becoupled to two R³-substituted thienyl groups to provide the monomer:

which then can be used to copolymerize with a repeating unit pi-2 asshown below, where the azine is pyrazine and R³ is a 2-decyldodecylgroup:

or similarly, in the scheme below, where the azine is pyridine and R³ isa dodecyl group:

The schemes below illustrate yet further possible syntheses foradditional polymers according to the present teachings:

Without wishing to be bound by any particular theory, it is believedthat polymers of the present teachings that have a regioregularpolymeric backbone can lead to higher molecular weights, a moreπ-conjugated structure and, consequently better charge transportefficiencies. Accordingly, in preparing the present polymers, thepresent teachings can include isolating a particular average molecularweight fractions, and/or enriching and/or isolating a particularstereoisomer of M₁ and/or M₂ that has two or more stereoisomers.

Using coupling reactions analogous to those described above inconnection with the preparation of the present polymers, variousmolecular semiconducting compounds according to the present teachingscan be prepared by reacting different mono- or di-halogenated/metallatedderivatives of azino[1,2,3]thiadiazoles and spacer groups as illustratedbelow:

The semiconducting compounds disclosed herein can be stable in ambientconditions (“ambient stable”) and soluble in common solvents. As usedherein, a compound can be considered electrically “ambient stable” or“stable at ambient conditions” when the carrier mobility or thereduction-potential of the compound is maintained at about its initialmeasurement when the compound is exposed to ambient conditions, forexample, air, ambient temperature, and humidity, over a period of time.For example, a compound according to the present teachings can bedescribed as ambient stable if its carrier mobility or redox potentialdoes not vary more than 20% or more than 10% from its initial valueafter exposure to ambient conditions, including, air, humidity andtemperature, over a 3 day, 5 day, or 10 day period. In addition, acompound can be considered ambient stable if the optical absorption ofthe corresponding film does not vary more than 20% (preferably, does notvary more than 10%) from its initial value after exposure to ambientconditions, including air, humidity and temperature, over a 3 day, 5day, or 10 day period.

OTFTs based on the present compounds can have long-term operability andcontinued high-performance in ambient conditions. For example, OTFTsbased on certain embodiments of the present compounds can maintainsatisfactory device performance in highly humid environment. Certainembodiments of the present compounds also can exhibit excellent thermalstability over a wide range of annealing temperatures. Photovoltaicdevices can maintain satisfactory power conversion efficiencies over anextended period of time.

As used herein, a compound can be considered soluble in a solvent whenat least 0.1 mg of the compound can be dissolved in 1 mL of the solvent.Examples of common organic solvents include petroleum ethers;acetonitrile; aromatic hydrocarbons such as benzene, toluene, xylene,and mesitylene; ketones such as acetone, and methyl ethyl ketone; etherssuch as tetrahydrofuran, dioxane, bis(2-methoxyethyl) ether, diethylether, di-isopropyl ether, and t-butyl methyl ether; alcohols such asmethanol, ethanol, butanol, and isopropyl alcohol; aliphatichydrocarbons such as hexanes; esters such as methyl acetate, ethylacetate, methyl formate, ethyl formate, isopropyl acetate, and butylacetate; amides such as dimethylformamide and dimethylacetamide;sulfoxides such as dimethylsulfoxide; halogenated aliphatic and aromatichydrocarbons such as dichloromethane, chloroform, ethylene chloride,chlorobenzene, dichlorobenzene, and trichlorobenzene; and cyclicsolvents such as cyclopentanone, cyclohexanone, and 2-methypyrrolidone.The present compounds can have room temperature solubilities inconventional organic solvents such as xylene, dichlorobenzene (DCB), andother chlorinated hydrocarbons (CHCs) as high as 60 g/L.

The present compounds can be fabricated into various articles ofmanufacture using solution processing techniques in addition to othermore expensive processes such as vapor deposition. Various solutionprocessing techniques have been used with organic electronics. Commonsolution processing techniques include, for example, spin coating,drop-casting, zone casting, dip coating, blade coating, or spraying.Another example of solution processing technique is printing. As usedherein, “printing” includes a noncontact process such as inkjetprinting, microdispensing and the like, and a contact process such asscreen-printing, gravure printing, offset printing, flexographicprinting, lithographic printing, pad printing, microcontact printing andthe like.

Compounds of the present teachings can be used to prepare semiconductormaterials (e.g., compositions and composites), which in turn can be usedto fabricate various articles of manufacture, structures, and devices.In some embodiments, semiconductor materials incorporating one or morecompounds of the present teachings can exhibit n-type semiconductoractivity, ambipolar activity, light absorption, and light emission.

The present teachings, therefore, further provide methods of preparing asemiconductor material. The methods can include preparing a compositionthat includes one or more compounds disclosed herein dissolved ordispersed in a liquid medium such as a solvent or a mixture of solvents,depositing the composition on a substrate to provide a semiconductormaterial precursor, and processing (e.g., heating) the semiconductorprecursor to provide a semiconductor material (e.g., a thin filmsemiconductor) that includes a compound disclosed herein. In variousembodiments, the liquid medium can be an organic solvent, an inorganicsolvent such as water, or combinations thereof. In some embodiments, thecomposition can further include one or more additives independentlyselected from viscosity modulators, detergents, dispersants, bindingagents, compatibilizing agents, curing agents, initiators, humectants,antifoaming agents, wetting agents, pH modifiers, biocides, andbacteriostats. For example, surfactants and/or polymers (e.g.,polystyrene, polyethylene, poly-alpha-methylstyrene, polyisobutene,polypropylene, polymethylmethacrylate, and the like) can be included asa dispersant, a binding agent, a compatibilizing agent, and/or anantifoaming agent. In some embodiments, the depositing step can becarried out by printing, including inkjet printing and various contactprinting techniques (e.g., screen-printing, gravure printing, offsetprinting, pad printing, lithographic printing, flexographic printing,and microcontact printing). In other embodiments, the depositing stepcan be carried out by spin coating, drop-casting, zone casting, dipcoating, blade coating, or spraying.

Various articles of manufacture including electronic devices, opticaldevices, and optoelectronic devices, such as thin film semiconductors,field effect transistors (e.g., thin film transistors), photovoltaics,photodetectors, organic light emitting devices such as organic lightemitting diodes (OLEDs) and organic light emitting transistors (OLETs),complementary metal oxide semiconductors (CMOSs), complementaryinverters, diodes, capacitors, sensors, D flip-flops, rectifiers, andring oscillators, that make use of the compounds disclosed herein arewithin the scope of the present teachings as are methods of making thesame. The present compounds can offer processing and operationadvantages in the fabrication and/or the use of these devices. Forexample, articles of manufacture such as the various devices describedherein can include a composite having a semiconductor material of thepresent teachings and a substrate component and/or a dielectriccomponent. The substrate component can be selected from doped silicon,an indium tin oxide (ITO), ITO-coated glass, ITO-coated polyimide orother plastics, aluminum or other metals alone or coated on a polymer orother substrate, a doped polythiophene, and the like. The dielectriccomponent can be prepared from inorganic dielectric materials such asvarious oxides (e.g., SiO₂, Al₂O₃, HfO₂), organic dielectric materialssuch as various polymeric materials (e.g., polycarbonate, polyester,polystyrene, polyhaloethylene, polyacrylate), and self-assembledsuperlattice/self-assembled nanodielectric (SAS/SAND) materials (e.g.,described in Yoon, M -H. et al., PNAS, 102 (13): 4678-4682 (2005), theentire disclosure of which is incorporated by reference herein), as wellas hybrid organic/inorganic dielectric materials (e.g., described inU.S. patent application Ser. No. 11/642,504, the entire disclosure ofwhich is incorporated by reference herein). In some embodiments, thedielectric component can include the crosslinked polymer blendsdescribed in U.S. patent application Ser. Nos. 11/315,076, 60/816,952,and 60/861,308, the entire disclosure of each of which is incorporatedby reference herein. The composite also can include one or moreelectrical contacts. Suitable materials for the source, drain, and gateelectrodes include metals (e.g., Au, Al, Ni, Cu), transparent conductingoxides (e.g., ITO, IZO, ZITO, GZO, GIO, GITO), and conducting polymers(e.g., poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate)(PEDOT:PSS), polyaniline (PANT), polypyrrole (PPy)). One or more of thecomposites described herein can be embodied within various organicelectronic, optical, and optoelectronic devices such as organic thinfilm transistors (OTFTs), specifically, organic field effect transistors(OFETs), as well as sensors, capacitors, unipolar circuits,complementary circuits (e.g., inverter circuits), and the like.

Other articles of manufacture in which compounds of the presentteachings are useful are photovoltaics or solar cells. Particularly,polymers of the present teachings can exhibit broad optical absorptionand/or a tuned redox properties and bulk carrier mobilities, making themdesirable for such applications. For example, the polymers describedherein can be used as a donor (p-type) semiconductor in a photovoltaicdesign, which includes an adjacent n-type semiconductor material thatforms a p-n junction. The polymers can be in the form of a thin filmsemiconductor, which can be deposited on a substrate to form acomposite. Exploitation of polymers of the present teachings in suchdevices is within the knowledge of a skilled artisan.

Accordingly, another aspect of the present teachings relates to methodsof fabricating an organic field effect transistor that incorporates asemiconductor material of the present teachings. The semiconductormaterials of the present teachings can be used to fabricate varioustypes of organic field effect transistors including top-gate top-contactcapacitor structures, top-gate bottom-contact capacitor structures,bottom-gate top-contact capacitor structures, and bottom-gatebottom-contact capacitor structures. FIG. 1 illustrates the four commontypes of OFET structures: (a) bottom-gate top-contact structure, (b)bottom-gate bottom-contact structure, (c) top-gate bottom-contactstructure, and (d) top-gate top-contact structure. As shown in FIG. 1,an OFET can include a dielectric layer (e.g., shown as 8, 8′, 8″, and8′″ in FIGS. 1a, 1b, 1c, and 1d , respectively), a semiconductor/channellayer (e.g., shown as 6, 6′, 6″, and 6′″ in FIGS. 1a, 1b, 1c, and 1d ,respectively), a gate contact (e.g., shown as 10, 10′, 10″, and 10′″ inFIGS. 1a, 1b, 1c, and 1d , respectively), a substrate (e.g., shown as12, 12′, 12″, and 12′″ in FIGS. 1a, 1b, 1c, and 1d , respectively), andsource and drain contacts (e.g., shown as 2, 2′, 2″, 2′″, 4, 4′, 4″, and4′″ in FIGS. 1a, 1b, 1c, and d , respectively).

In certain embodiments, OTFT devices can be fabricated with the presentsemiconducting compounds on doped silicon substrates, using SiO₂ as thedielectric, in top-contact geometries. In particular embodiments, theactive semiconductor layer which incorporates at least a semiconductingcompound of the present teachings can be deposited at room temperatureor at an elevated temperature. In other embodiments, the activesemiconductor layer which incorporates at least one semiconductingcompound of the present teachings can be applied by spin-coating orprinting as described herein. For top-contact devices, metallic contactscan be patterned on top of the films using shadow masks.

In certain embodiments, OTFT devices can be fabricated with the presentcompounds on plastic foils, using polymers as the dielectric, intop-gate bottom-contact geometries. In particular embodiments, theactive semiconducting layer which incorporates at least a semiconductingcompound of the present teachings can be deposited at room temperatureor at an elevated temperature. In other embodiments, the activesemiconducting layer which incorporates at least a semiconductingcompound of the present teachings can be applied by spin-coating orprinting as described herein. Gate and source/drain contacts can be madeof Au, other metals, or conducting polymers and deposited byvapor-deposition and/or printing.

Similarly, another aspect of the present teachings relates to methods offabricating an organic light-emitting transistor, an organiclight-emitting diode (OLED), or an organic photovoltaic device thatincorporates one or more semiconductor materials of the presentteachings. FIG. 2 illustrates a representative structure of abulk-heterojunction organic photovoltaic device (also known as solarcell) which can incorporate one or more semiconducting compounds of thepresent teachings as the donor material. As shown, a representativesolar cell generally includes a substrate 20 (e.g., glass), an anode 22(e.g., ITO), a cathode 26 (e.g., aluminium or calcium), and an activelayer 24 between the anode and the cathode which can incorporate one ormore semiconducting compounds of the present teachings as the electrondonor (p-channel) materials. FIG. 3 illustrates a representativestructure of an OLED which can incorporate one or more semiconductingcompounds of the present teachings as electron-transporting and/oremissive and/or hole-transporting materials. As shown, an OLED generallyincludes a substrate 30 (not shown), a transparent anode 32 (e.g., ITO),a cathode 40 (e.g., metal), and one or more organic layers which canincorporate one or more semiconducting compounds of the presentteachings as hole-transporting (n-channel) (layer 34 as shown) and/oremissive (layer 36 as shown) and/or electron-transporting (p-channel)materials (layer 38 as shown).

Molecular orbital (MO) calculations (B3LYP/6-31G*) (Spartan'08Wavefunction, Inc. Irvine, Calif.) were carried out to compare vis-à-visthe geometrical parameters, electronic structures, and HOMO/LUMO energylevels of conventional dithienyl substituted benzo[1,2,5]thiadiazole andbenzo[1,2,3]thiadiazole derivatives versus those of the azine-basedsystems disclosed herein. Table 1 below summarizes the chemicalstructures, frontier molecular orbital energy values, and molecularorbital topology for the indicated thiadiazole units. These datademonstrate that the new cores according to the present teachings areall very planar, which is essential for good charge transport for thecorresponding molecular and polymeric semiconductors. Interestingly, theresults show that all of the azine systems exhibit much lower HOMOenergies whereas, surprisingly, the energy level of the LUMO varies to alesser extent and the variation depends on the regiochemistry of thenitrogen position (6 vs. 7) and the number of nitrogen (1 vs. 2) atoms.Thus, the inventors expect that when combining the new azinethiazole orthe dithienyl-azinethiazoles with an electron donor co-monomer (e.g.,dithiophene, terthiophene, quaterthiophene, thienothiophene,dithienobenzene, and so forth), the corresponding polymers should behole-transporting and should have large Voc values compared to theconventional benzo[1,2,5]thiadiazole-based andbenzo[1,2,3]thiadiazole-based polymers. Furthermore, when combining theazinethiazole or the dithienyl-azinethiazoles with a strongelectron-acceptor co-monomer (e.g., naphthalenediimide,diketopyrrolopyrrole, and so forth), electron transport should bepromoted, thus these polymers in those embodiments could function aselectron transporters.

All publications, including but not limited to patents and patentapplications, cited in this specification are herein incorporated byreference as if each individual publication were specifically andindividually indicated to be incorporated by reference herein as thoughfully set forth.

The present teachings encompass embodiments in other specific formswithout departing from the spirit or essential characteristics thereof.The foregoing embodiments are therefore to be considered in all respectsillustrative rather than limiting on the present teachings describedherein. Scope of the present invention is thus indicated by the appendedclaims rather than by the foregoing description, and all changes thatcome within the meaning and range of equivalency of the claims areintended to be embraced therein.

What is claimed is:
 1. A semiconducting compound comprising one or moreazino[1,2,3]thiadiazole moieties represented by formula (I):

wherein: each W independently is selected from the group consisting ofN, CH, and CR¹, provided that at least one of the W is N; and R¹ isselected from the group consisting of halogen, —CN, NO₂, R², -L-R³, OH,OR², OR³, NH₂, NNR², N(R²)₂, NR²R³, N(R³)₂, SH, SR², SR³, S(O)₂OH,—S(O)₂OR², —S(O)₂OR³, C(O)H, C(O)R², C(O)R³, C(O)OH, C(O)OR², C(O)OR³,C(O)NH₂, C(O)NHR², C(O)N(R²)₂, C(O)NR²R³, C(O)N(R³)₂, SiH₃, SiH(R²)₂,SiH₂(R²), and Si(R²)₃, wherein L is selected from the group consistingof a divalent C₁₋₄₀ alkyl group, a divalent C₂₋₄₀ alkenyl group, adivalent C₁₋₄₀ haloalkyl group, and a covalent bond; R² is selected fromthe group consisting of a C₁₋₄₀ alkyl group, a C₂₋₄₀ alkenyl group, aC₂₋₄₀ alkynyl group, and a C₁₋₄₀ haloalkyl group; and R³ is selectedfrom the group consisting of a C₃₋₁₀ cycloalkyl group, a C₆₋₁₄ arylgroup, a C₆₋₁₄ haloaryl group, a 3-12 membered cycloheteroalkyl group,and a 5-14 membered heteroaryl group, each of which optionally issubstituted with 1-5 substituents independently selected from the groupconsisting of halogen, —CN, NO₂, R², OR², and SR².
 2. The compound ofclaim 1, wherein R¹ is selected from the group consisting of F, Cl, —CN,—NO₂, R², OR², and SR², wherein R² is selected from the group consistingof a linear or branched C₁₋₄₀ alkyl group, a linear or branched C₂₋₄₀alkenyl group, and a linear or branched C₁₋₄₀ haloalkyl group.
 3. Thecompound of claim 1, wherein one of the W is N and the other W is CR¹,wherein R¹ is selected from the group consisting of F, Cl, and a C₁₋₄₀alkyl group.
 4. The compound of claim 1, wherein one of the W is N andthe other W is selected from the group consisting of N, CH, CF, and CCl.5. The compound of claim 1, wherein the compound is a polymer having afirst repeating unit M₁ comprising one or more divalent unitsrepresented by formula (I) and wherein said polymer has a degree ofpolymerization (n) ranging from 3 to 1,000.
 6. The compound of claim 5,wherein M₁ is selected from the group consisting of:

wherein: pi-2 is an optionally substituted C₈₋₂₆ aryl group or 8-26membered heteroaryl group; Ar, at each occurrence, is independently anoptionally substituted 5- or 6-membered aryl or heteroaryl group; Z is aconjugated noncyclic linker; m and m′ independently are 0, 1, 2, 3, 4, 5or 6, provided that at least one of m and m′ is not 0; and p and p′independently are 0 and 1, provided that at least one of p and p′ is 1.7. The compound of claim 6, wherein pi-2 is selected from the groupconsisting of:

wherein: R^(a) is selected from the group consisting of H, F, Cl, —CN,R, —OR, —SR, —C(O)R, —OC(O)R, and —C(O)OR; R^(b) is selected from thegroup consisting of H, R, and -L-R^(f); R^(c) is H or R; R^(d) isselected from the group consisting of H, F, Cl, —CN, R, —OR, —SR,—C(O)R, —OC(O)R, —C(O)OR, and -L-R^(f); R^(e) is selected from the groupconsisting of H, F, Cl, —CN, R, —OR, —SR, —C(O)R, —OC(O)R, —C(O)OR, andR^(f); R^(f) is a C₆₋₂₀ aryl group or a 5-20-membered heteroaryl group,each optionally substituted with 1-8 groups independently selected fromthe group consisting of F, Cl, —CN, R, —OR, and —SR; L is selected fromthe group consisting of —O—, —S—, —C(O)—, —OC(O)—, —C(O)O—, and acovalent bond; and R is selected from the group consisting of a C₁₋₄₀alkyl group, a C₁₋₄₀ haloalkyl group, a C₂₋₄₀ alkenyl group, and a C₂₋₄₀alkynyl group.
 8. The compound of claim 6, wherein Ar in (Ar)_(m) and(Ar)_(m′) is represented by:

wherein each X independently is selected from the group consisting of N,CH, and CR⁴, wherein R⁴ is selected from the group consisting of F, Cl,—CN, R², OR², SR², C(O)R², OC(O)R², and C(O)OR², and wherein R² isselected from the group consisting of a C₁₋₄₀ alkyl group, a C₂₋₄₀alkenyl group, a C₂₋₄₀ alkynyl group, and a C₁₋₄₀ haloalkyl group. 9.The compound of claim 8, wherein (Ar)_(m) and (Ar)_(m′) independentlyare selected from the group consisting of:

wherein R⁴, at each occurrence, independently is selected from the groupconsisting of F, Cl, CN, R², OR², and SR², where R² is a linear orbranched C₁₋₄₀ alkyl or haloalkyl group.
 10. The compound of claim 6,wherein Z is selected from the group consisting of:

wherein R⁴ is selected from the group consisting of F, Cl, —CN, R², OR²,SR², C(O)R², OC(O)R², and C(O)OR², and wherein R² is selected from thegroup consisting of a C₁₋₄₀ alkyl group, a C₂₋₄₀ alkenyl group, a C₂₋₄₀alkynyl group, and a C₁₋₄₀ haloalkyl group.
 11. The compound of claim 6,further comprising one or more repeating units other than M₁, the one ormore other repeating units (M₂) being selected from the group consistingof:

wherein: pi-2 is an optionally substituted conjugated polycyclic moiety;Ar, at each occurrence, is independently an optionally substituted 5- or6-membered aryl or heteroaryl group; Z is a conjugated noncyclic linker;m and m′ independently are 0, 1, 2, 3, 4, 5 or 6, provided that at leastone of m and m′ is not 0; m″ is 1, 2, 3, 4, 5 or 6; and p and p′independently are 0 and 1, provided that at least one of p and p′ is 1.12. The compound of claim 11, wherein in the one or more M₂ repeatingunits, Z is selected from the group consisting of:

(Ar)_(m), (Ar)_(m′), and (Ar)_(m″) independently are selected from thegroup consisting of:

wherein R⁴ is selected from F, Cl, —CN, R², OR², SR², C(O)R², OC(O)R²,and C(O)OR², and wherein R² is selected from a C₁₋₄₀ alkyl group, aC₂₋₄₀ alkenyl group, a C₂₋₄₀ alkynyl group, and a C₁₋₄₀ haloalkyl group;and pi-2 is selected from the group consisting of:

wherein: R^(a) is selected from the group consisting of H, F, Cl, —CN,R, —OR, —SR, —C(O)R, —OC(O)R, and —C(O)OR; R^(b) is selected from thegroup consisting of H, R, and -L-R^(f); R^(c) is H or R; R^(d) isselected from the group consisting of H, F, Cl, —CN, R, —OR, —SR,—C(O)R, —OC(O)R, —C(O)OR, and -L-R^(f); and R^(e) is selected from thegroup consisting of H, F, Cl, —CN, R, —OR, —SR, —C(O)R, —OC(O)R,—C(O)OR, and R^(f); wherein R^(f) is a C₆₋₂₀ aryl group or a5-20-membered heteroaryl group, each optionally substituted with 1-8groups independently selected from the group consisting of F, Cl, —CN,R, —OR, and —SR; L is selected from the group consisting of —O—, —S—,—C(O)—, —OC(O)—, —C(O)O—, and a covalent bond; and R is selected fromthe group consisting of a C₁₋₄₀ alkyl group, a C₁₋₄₀ haloalkyl group, aC₂₋₄₀ alkenyl group, and a C₂₋₄₀ alkynyl group; and R is selected fromthe group consisting of a C₁₋₄₀ alkyl group, a C₁₋₄₀ haloalkyl group, aC₂₋₄₀ alkenyl group, and a C₂₋₄₀ alkynyl group.
 13. The compound ofclaim 12, wherein M₁ is selected from the group consisting of:

wherein R⁴ is selected from the group consisting of R², OR², and SR²,where R² is a linear or branched C₁₋₄₀ alkyl or haloalkyl group; and M₂is selected from the group consisting of:

wherein (Ar)_(m) and (Ar)_(m′) are selected from the group consistingof:


14. The compound of claim 13, wherein the compound is a random copolymerhaving a formula selected from the group consisting of:

wherein M_(1A) and M_(1B) represent different repeating units M₁, andM_(2A) and M_(2B) represent different repeating units M₂, x and y arereal numbers representing molar ratios, and n is the degree ofpolymerization.
 15. The compound of claim 1, wherein the compound is asmall molecule represented by a formula selected from the groupconsisting of:

wherein: Q¹ and Q² independently are selected from the group consistingof H, R², and C(O)R², wherein R² is a C₁₋₄₀ alkyl or haloalkyl group;pi-2 is an optionally substituted conjugated polycyclic moiety; Ar, ateach occurrence, is independently an optionally substituted 5- or6-membered aryl or heteroaryl group; Z is a conjugated noncyclic linker;m and m′ independently are 0, 1, 2, 3, 4, 5 or 6, provided that at leastone of m and m′ is not 0; m″ is 1, 2, 3, 4, 5 or 6; and p and p′independently are 0 and 1, provided that at least one of p and p′ is 1.16. The compound of claim 15, wherein the compound is represented by aformula selected from the group consisting of:


17. The compound of claim 16 selected from the group consisting of:


18. An electronic, optical or optoelectronic device comprising asemiconductor component, the semiconductor component comprising acompound of claim
 1. 19. An organic photovoltaic device comprising ananode, a cathode, optionally one or more anode interlayers, optionallyone or more cathode interlayers, and in between the anode and thecathode a semiconductor component comprising a blend material, the blendmaterial comprising an electron-acceptor compound and an electron-donorcompound, the electron-donor compound being a compound of claim
 1. 20.An organic thin film transistor comprising a substrate, a thin filmsemiconductor, a dielectric layer, a gate electrode, and source anddrain electrodes, wherein the thin film semiconductor comprises acompound of claim 1.